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Fermi LAT detection of a possible new gamma-ray blazar: GB6 J1700+6830

ATEL # 1986; D. Gasparrini (ASI Science Data Center), A. B. Hill (LAOG); on behalf of the Fermi Large Area Telescope Collaboration
on 23 Mar 2009; 18:50 UT
Distributed as an Instant Email Notice (Request for Observations)
Password Certification: Paolo Giommi (

Subjects: Gamma Ray, >GeV, AGN, Quasars
Referred to by ATEL #: 1991

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope (formerly GLAST, launched June 11, 2008), has observed an increasing gamma-ray flux from a source positionally consistent with GB6 J1700+6830 (RA: 17h00m09.2928s, Dec: +68d30m06.962s , J2000, Beasley, A. J et al., 2002. ApJS,141,13B ) since Mar. 20, 2009.

This object is a known Flat Spectrum Radio Quasar (z= 0.301 +/- 0.001, D. R. Henstock et al., 1997, MNRAS, 290, 380H) also reported in the five-year WMAP point source catalog (E.L. Wright et al., 2009, ApJS 180, 283W).

Preliminary analysis indicates that on Mar. 22, 2009 the source was in a high state with a gamma-ray flux (E>100MeV) of 0.99+/-0.21 x 10^-6 ph cm^-2 s^-1 on a daily time scale, and reaching a value of 1.79+/-0.56 x 10^-6 ph cm^-2 s^-1 on a six-hour time scale starting from 12:00:00 (UT) of the same day. The source was not detected previously by the LAT and there is no previously reported EGRET gamma-ray detection at this location.

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the ongoing activity of this source we strongly encourage multiwavelength observations. For this source the Fermi LAT contact person is Sara Cutini (

The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.

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